summaryrefslogtreecommitdiff
path: root/drivers/hwmon/ads7828.c
diff options
context:
space:
mode:
authorStefan Agner <stefan.agner@toradex.com>2016-06-29 17:36:47 -0700
committerStefan Agner <stefan.agner@toradex.com>2016-06-29 17:36:47 -0700
commitefe965a5dad66bd14219cdc9474ea75eda783456 (patch)
treec88aa38447747bee19da6e4097334cd4c98b426f /drivers/hwmon/ads7828.c
parent475764ae387355462c874892b03110298038adef (diff)
parent9ca1d50fa959cda1f04f43275f7930a70f1a631e (diff)
Merge tag 'v4.4.14' into toradex_vf_4.4-nextColibri_VF_LinuxImageV2.6Beta2_20160701
This is the 4.4.14 stable release
Diffstat (limited to 'drivers/hwmon/ads7828.c')
-rw-r--r--drivers/hwmon/ads7828.c10
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/hwmon/ads7828.c b/drivers/hwmon/ads7828.c
index 6c99ee7bafa3..ee396ff167d9 100644
--- a/drivers/hwmon/ads7828.c
+++ b/drivers/hwmon/ads7828.c
@@ -120,6 +120,7 @@ static int ads7828_probe(struct i2c_client *client,
unsigned int vref_mv = ADS7828_INT_VREF_MV;
bool diff_input = false;
bool ext_vref = false;
+ unsigned int regval;
data = devm_kzalloc(dev, sizeof(struct ads7828_data), GFP_KERNEL);
if (!data)
@@ -154,6 +155,15 @@ static int ads7828_probe(struct i2c_client *client,
if (!diff_input)
data->cmd_byte |= ADS7828_CMD_SD_SE;
+ /*
+ * Datasheet specifies internal reference voltage is disabled by
+ * default. The internal reference voltage needs to be enabled and
+ * voltage needs to settle before getting valid ADC data. So perform a
+ * dummy read to enable the internal reference voltage.
+ */
+ if (!ext_vref)
+ regmap_read(data->regmap, data->cmd_byte, &regval);
+
hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
data,
ads7828_groups);